*{
    margin:0;
    padding:0;
}
.circle{
    width:80px;
    height:80px;
    border-radius:50%;
    position: absolute;
    border-style:solid;
    border-width: 5px;
}
.blue{
    border-color: blue;
    top:20px;
    left:20px;
}
.green{
    border-color: green;
    top:60px;
    left:170px;
}
.red{
    border-color: red;
    top:20px;
    left:220px;
}
.black{
    border-color: black;
    top:20px;
    left:120px;
}
.yellow{
    border-color: yellow;
    top:60px;
    left:70px;
}
.main{
    width:350px;
    height:180px;
    position: fixed;
    top:50%;
    left:50%;
    margin:-175px 0 0 -175px;
    /* border:1px solid lightgreen; */
}